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11.
Alexander Pyattaev Jiri Hosek Kerstin Johnsson Radko Krkos Mikhail Gerasimenko Pavel Masek Aleksandr Ometov Sergey Andreev Jakub Sedy Vit Novotny Yevgeni Koucheryavy 《ETRI Journal》2015,37(5):877-887
This paper is a first‐hand summary on our comprehensive live trial of cellular‐assisted device‐to‐device (D2D) communications currently being ratified by the standards community for next‐generation mobile broadband networks. In our test implementation, we employ a full‐featured 3GPP LTE network deployment and augment it with all necessary support to provide real‐time D2D connectivity over emerging Wi‐Fi‐Direct (WFD) technology. As a result, our LTE‐assisted WFD D2D system enjoys the required flexibility while meeting the existing standards in every feasible detail. Further, this paper provides an account on the extensive measurement campaign conducted with our implementation. The resulting real‐world measurements from this campaign quantify the numerical effects of D2D functionality on the resultant system performance. Consequently, they shed light on the general applicability of LTE‐assisted WFD solutions and associated operational ranges. 相似文献
12.
The aim of the present study was to characterize the intestinal absorption of retinol and retinyl palmitate in thoracic duct
and bile duct fistulated rats and to investigate the effect of a simultaneously administered lipase inhibitor, tetrahydrolipstatin
(THL). Absorption was determined as lymphatic recovery over a 24-hr period, including an initial 12-hr continuous intraduodenal
infusion of either [11,12-3H]retinol or [11,12-3H]retinyl palmitate given in emulsified glyceryl trioleate or in mixed micellar solution of monoolein and oleic acid. From
micellar dispersion, labeled retinol and retinyl palmitate were recovered in the lymph to 50–60% and both to the same extent.
Administered in emulsified form, labeled retinol from fed retinyl palmitate was recovered to 47%, but retinol from fed retinol
to only 18%. THL (10−4 M) in the infusate had no significant effect on the recovery of14C-labeled oleic acid. The recovery of label from emulsified glyceryl tri[1-14C]oleate was significantly decreased at this concentration of THL (76.5% vs 19.6% recovery). When administered in emulsified
form, retinol absorption was not significantly affected by THL at 10−4 M, while retinyl palmitate absorption was very significantly decreased (5.0% compared to 47.8%). In the presence of THL,
retinol absorption from retinyl palmitate in micellar solution was decreased (from 58% to 17%). Most of the retinol in the
lymph extracts (72.2 to 91.3) was present as retinyl ester, regardless of the chemical and physical form of administration.
Furthermore, THL did not induce any change in this pattern. 相似文献
13.
1 牛奶牛奶含有多种人体所需的营养成分和维生素 ,如维生素A和D等 ,是我们膳食的重要组成部分。研究发现 ,牛奶的营养组成比例是最接近人奶的天然食品。随着生活水平的不断提高和商品供给的日益丰富 ,消费者的需求也不仅仅局限于普通白奶了。多种风味奶、脱脂奶、强化奶及低乳糖牛奶应运而生。通常 ,我们讲到的“奶”是指牛奶 ,但在世界各地 ,由于地理条件 ,气候环境不同 ,也有很多其他品种供应 ,例如水牛奶、骆驼奶、山羊奶、豆奶、大麦奶等等。不同类型的奶往往要求不同的加工工艺和手段 ,以尽可能地保持原料奶中的营养成分和特有风味… 相似文献
14.
The construction industry is based on craftsmanship. Quality control and assurance procedures applied in manufacturing cannot usually be readily applied in construction, where there are higher degrees of uniqueness in each project. One category of companies, industrialized housebuilders, is attempting to bridge some of the gaps between construction and manufacturing. These companies prefabricate building modules for later assembly at the building site. Since they are wholly responsible for large parts of the building process, these companies have greater opportunities to control and improve quality in a more consistent way than ordinary construction companies. Thus, it could be hypothesized that the frequency and severity of defects should be lower in industrialized housing than in ordinary construction. The aim of the study presented here is to examine this hypothesis by measuring and characterizing defects in industrialized housing. The design and manufacturing processes at two Swedish timber module prefabrication firms has been analysed through interviews, site visits and document reviews. Quality audits from three phases of the building process were compiled, analysed and categorized to provide statistical measures of defects in industrialized housing. The results show that the case study companies are better in terms of product quality than conventional housing. 相似文献
15.
In construction projects, a large number of deviations are usually found during inspections and adjusted in a reactive manner. For projects to become proactive, root causes need to be identified and eliminated as a part of a process of continuous improvement (CI). Plan-do-check-act (PDCA) methods are part of CI and have been used with success within the manufacturing industry for decades. Research studies of PDCA in construction are less common, which could be explained by the past dominance of the project-based nature of construction compared to the process-based nature of manufacture. Industrialized construction, however, has changed this picture somewhat, and it is of interest to find out how well it works for less industrialized activities in construction. A PDCA method was tested in two cases selected from one medium-sized Swedish industrialized housebuilder, which uses a building system based on offsite manufactured modules. Empirical results are based on systematic data gathered through interviews and participant observations. Results from the two cases show that the PDCA method worked even when processes were divided into industrialized parts within a factory and non-industrial parts at the construction site although this might lead to temporary corrective actions rather than permanent process actions. 相似文献
16.
A bulk surface photografting process which is conducted in the interface between two polymer films was designed and investigated. The bulk surface photografting is a highly efficient process. With this method, the surface of hydrophobic polymers can be made hydrophilic in less than 2 s and a grafted layer 5 μm thick can be obtained in 30 s. The kinetic investigation shows that the bulk surface photografting polymerization involves a four-step reaction process: induction period, surface initiation, successive polymerization, involves a four-step reaction process: induction period, surface initiation, successive polymerization, and solid-phase crosslinking. The photoreduction of benzophenone (BP) takes place in the interlayer between the LDPE films and is a three-stage process: surface photoreduction, secondary photoreduction, and solid-state photoreduction. With regard to the photoreduction of the initiator caused by hydrogen abstraction, the kinetic studies show that the photoreduction rate has a first-order dependence on the BP concentration. The activation energy of the hydrogen abstraction reaction is about 28.5 KJ (6.8 kcal)/mol. With regard to the photografting polymerization reaction, the reaction order of the rate Rp with respect to the monomer is unity and 0.89 with respect to BP. This means that the termination reaction takes place mainly by combination of polymer chain free radicals and semipinacol free radicals from BP. The activation energy of the overall polymerization reaction is around 8.8 kJ (2.1 kcal)/mol. © 1996 John Wiley & Sons, Inc. 相似文献
17.
Ann-Cathrine Lassas Lars E. Fagerholm Bengt G. Stelound Jan H. Nasman 《Polymer Composites》1993,14(1):1-6
The research reported in the article focuses on modifying glass fiber surfaces with polyacrylic acid (PAA) compounds. E-glass fibers were treated with aqueous polyacrylic acid solution. Polyacrylic acid exchanges its protons with the ions present in the glass surface. Hydrolyzed metal cations may form salt complexes with the dissociated polyacrylic acid. Angular dependent electron spectroscopy for chemical analysis (ESCA) demonstrated that the atomic concentrations of aluminum and calcium in the glass fiber surface were constant throughout the analyzed interval. The cation exchange property of glass fiber was studied using direct current plasma (DCP), which showed that both calcium and aluminum ions were extracted by low concentration polycrylic acid solutions. ESCA studies of were extracted by low concentrationb polyacrylic acid solutions. ESCA studies of the PAA-treated glass fiber showed that the amount of PAA of the glass surface increases with increased acid concentration. A broadened and shifted ESCA peak of the carbon (0 CO) indicates the formation of salt complexes between the polyacrylic acid and metal ions on the glass surface. Polyacrylie acid was modified by an esterification reaction with glycidyl acrylate (GA) in aqueous solution in order to insert organofuctional groups into the PAA chain. 相似文献
18.
Ming Chen Bengt Hallstedt A. Nicholas Grundy Ludwig J. Gauckler 《Journal of the American Ceramic Society》2003,86(9):1567-1570
Phase equilibria in the CeO2 −CoO system at temperatures above 1500°C were investigated. The microstructures and the phase compositions of the DTA (differential thermal analysis) samples and the quenched solid pellets were analyzed using SEM (scanning electron microscope), EDX (energy dispersive X-ray), and WDX (wavelength dispersive X-ray). A eutectic reaction was found at 1645 ± 5°C. The eutectic point was calculated to be at 82 ± 1.5 mol% CoO. The eutectic phases were the CeO2 -rich phase (containing <5 mol% CoO) and the CoO-rich phase (containing ∼0.5 mol% CeO2 ). At 1580°C, the solubility of CoO in CeO2 was ∼3 mol%. 相似文献
19.
This study presents a planning model for Swedish activities in the field of wind power. Models and results of calculations of the land-based wind energy potential with the Wind Atlas Analysis and Application Programme, WAsP, are described and analysed in a geographical information systems (GIS) called the ArcView® GIS system. One county in southern Sweden was chosen as a case study to present the methods used. The results from that case study indicate a great wind energy potential but there are nevertheless many factors limiting that potential. The study calls for a further development of planning tools in the field. Important areas for the future are the development of knowledge in market issues, wind power technology, environmental issues, and public opinion on constructing wind turbines. 相似文献
20.
The effect of reaction conditions on the composition of native potato starch–polyacrylonitrile graft copolymers initiated by manganic pyrophosphate onto starch slurries at 30°C has been examined. In general, when the Mn3+ ion concentration was increased from 0.15 × 10?3M to 3.0 × 10?3M (other conditions kept constant), an increase in conversion of monomer to polymer and % add-on was observed, whereas frequency of grafts (anhydroglucose units, AGU, per grafted chain) decreased. Also, the average molecular weights of grafts showed a decrease from 2.2 × 105 to 1.5 × 105. Increasing the concentration ratio of starch to monomer during polymerization by a factor of 3 produced an increase in the conversion of monomer to polymer, whereas an increase in frequency of grafts (AGU/chain) was obtained. Values of % add-on and average molecular weights of the grafts showed, however, a decreasing tendency. It was observed that grafting onto starch took place readily even at acid additions as low as 10 × 10?3M H2SO4 (pH ?1.8). Selective solvent extraction of homopolymer and extremely low conversions of monomer to polymer (0.1%–1.5%) in duplicate runs without addition of starch indicated that grafting efficiencies were high in all cases. An attempt has been made to interpret the results in terms of variations in factors such as initial ratio of (Mn3+)/(AGU), termination rate of acrylonitrile chain radicals by oxidation by Mn3+ ions, oxidation rate of radicals formed on anhydroglucose units by Mn3+ ions, and physical factors such as diffusion rate of Mn3+ ions through the polyacrylonitrile-grafted starch granules for terminating the radicals. 相似文献